Explanation

The standard model of soil formation (Jenny's factors) identifies five main factors: climate, organisms, relief, parent material, and time. However, some modern classifications or specific textbooks might list six by separating 'time' or adding another factor like 'topography' vs 'relief', but the most common answer in many agricultural science contexts for the number of controlling factors is often cited as 5 or sometimes 6 depending on the specific curriculum. Given the options, 6 is a plausible intended answer in some contexts, making D incorrect.